The episode starts with Alex doing some research work on a haunting sight. Suddenly, the house has it's own bad temper, and the lights fall out. Alex stumbles to the fusebox, but before she reaches the door, Nick enters in a strange condition. He attacks Alex, but she managed to strap him down on his bed. Then the struggle for Nicks life begins. As the episode grows, you'll see memories of Nicks past (also shown in previous episodes of Poltergeist), flasbacks from moments in his life which had an impact. The flasback starts with memories of Nicks already deceased brother and the encounter with a large demon. In between Alex finds out that Nick is suffering from a parasite called Mephisto. Due to a call with Derek she finds out how to cure him.